Rule 158
The European Patent Office as an International Searching Authority or International Preliminary Examining Authority

(1) In the case of Article 17, paragraph 3(a) PCT, an additional international search fee shall be paid for each further invention for which an international search is to be carried out.

(2) In the case of Article 34, paragraph 3(a) PCT, an additional fee for international preliminary examination shall be paid for each further invention for which the international preliminary examination is to be carried out.

(3)¹⁶⁹ Where an additional fee has been paid under protest, the European Patent Office shall examine the protest in accordance with Rule 40.2(c) PCT to Rule 40.2(e) PCT or Rule 68.3(c) PCT to Rule 68.3(e) PCT, subject to payment of the prescribed protest fee. Further details concerning the procedure shall be determined by the President of the European Patent Office.